What modern English expression comes from the Greek myth of Pandora’s jar?

The modern English expression from the Greek myth of Pandora’s jar is “Pandora’s box.” It describes a source of unforeseen troubles or complications that cannot easily be contained once released.

The phrase is based on the story recorded by Hesiod, although his ancient Greek text describes a pithos, or large storage jar, rather than a small box. The box wording became established through later Latin translation and European literary tradition, especially after Renaissance humanist usage.

In everyday English, opening Pandora’s box means starting a chain of problems by investigating, changing, or revealing something. The expression is often used in journalism, politics, science, and technology when one action creates many unexpected consequences.

The phrase is not the same as “Pandora’s jar,” even though that wording is closer to the earliest surviving account. Both refer to the same myth, but “Pandora’s box” is the standard idiom in modern English.